This is a 91 or 92 accord. Automatic transmission.

After a minor collision, the radiator and headlight was replaced by my
friend (not a mechanic...) with instructions from the net.

Soon after that, (recently) he had this problem: (Not always, but
happened more than once)

After the engine warmed up by driving a short while, when stopped at a
light (transmission in DRIVE), brake pressed, the car would shake and
sometimes stall out. However, moving the trans. to Neutral, the
engine is fine. Putting it in drive after releasing the brake and the
car drives fine.

No strange noise otherwise when driven.

Any ideas? Unfortunately, the car is in another city driven by my
friend's wife. Thats the description I was given. They're trying
to determine if the car is safe to drive, and if its worth fixing.